export interface Monitor {}
export class Monitor27 implements Monitor {}

export interface Host {}
export class LegendHost implements Host {}

export class Computer {
  monitor: Monitor;
  host: Host;
  constructor() {
    this.monitor = new Monitor27();
    this.host = new LegendHost();
  }
  start() {
    console.log("组装好了,可以开机了");
  }
}
// let computer = new Computer();
// computer.start();
